This invention relates to a process for recovering a cell wall protein from streptococcal bacteria. More particularly, the invention relates to a process for recovering a Fc-receptor from such bacteria.
Fc-receptors from bacteria and processes for recovering these are known and described in the literature. For example, U.S. Pat. No. 3,850,798 describes a process for recovering the Fc-receptor protein A from staphylococcal bacteria through enzymatic solubilization using the enzyme trypsin.
A similar process using fag-induced cell wall-decomposing enzyme has also been suggested for solubilization of Fc-reactive protein from group A streptococci. This latter process constitutes one example of the principle that, by decomposing the long sugar polymers and the cross-linking peptide-bridges in the cell wall, a solubilization of all substances which were bonded to this structure will result. Residues of the cell wall may be left on the solubilized molecules. Simultaneously with the solubilization, all soluble intracellular substances from the streptococcal bacteria are released in the obtained liquid, which therefore will be very complex.
The former process, which according to U.S. Pat. No. 3,850,798 can be used in connection with staphylococcal bacteria, is a more selective process. However, such process according to our knowledge has neither been used nor described in connection with streptococcal bacteria. On the contrary, such use with streptococcal bacteria should have been deemed to be non-operative in view of the results which presently are known with respect to the protein nature of Fc-receptors and the sensitivity of these surface structures to proteolytic treatment. As a rule, a complete degradation of the proteins to amino acids and peptides are obtained, and all biological activity is lost.